JPX PUL 425
Two JPX PUL 425s mounted on a Lazair 2
The JPX PUL 425, also called simply the JPX 425, is a French twin-cylinder, horizontally opposed, two-stroke aircraft engine.
The engine was produced only until the company went out of business in the early 1990s. The company was re-formed but the engine remains out of production and unsupported for parts.
The engine has two cylinders in a horizontally-opposed configuration, with cooling fins on the cylinders. The single ignition system uses a coil and points. Fuel is metered by a single Tillotson butterfly-type carburetor. Starting is by a recoil starter system with electric start as an option.
The 425 has a redline rpm of 4600 and does not use a reduction drive. Its weight of just 38 lb (17 kg) gives the engine a high power-to-weight ratio.
Lazair Series III
Type: twin-cylinder, two-stroke engine
Displacement: 424 cc (25.87 cu inches)
Dry weight: 38 lb (17 kg)
Fuel system: Tillotson butterfly-type carburetor
Oil system: premixed oil and fuel
Cooling system: air cooled
Power output: 26 hp (19 kW) at 4600 rpm